pro_epilogue.c

 1// SPDX-License-Identifier: GPL-2.0-only
 2/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
 3
 4#include <test_progs.h>
 5#include "pro_epilogue.skel.h"
 6#include "epilogue_tailcall.skel.h"
 7#include "pro_epilogue_goto_start.skel.h"
 8#include "epilogue_exit.skel.h"
 9#include "pro_epilogue_with_kfunc.skel.h"
10
11struct st_ops_args {
12	__u64 a;
13};
14
15static void test_tailcall(void)
16{
17	LIBBPF_OPTS(bpf_test_run_opts, topts);
18	struct epilogue_tailcall *skel;
19	struct st_ops_args args;
20	int err, prog_fd;
21
22	skel = epilogue_tailcall__open_and_load();
23	if (!ASSERT_OK_PTR(skel, "epilogue_tailcall__open_and_load"))
24		return;
25
26	topts.ctx_in = &args;
27	topts.ctx_size_in = sizeof(args);
28
29	skel->links.epilogue_tailcall =
30		bpf_map__attach_struct_ops(skel->maps.epilogue_tailcall);
31	if (!ASSERT_OK_PTR(skel->links.epilogue_tailcall, "attach_struct_ops"))
32		goto done;
33
34	/* Both test_epilogue_tailcall and test_epilogue_subprog are
35	 * patched with epilogue. When syscall_epilogue_tailcall()
36	 * is run, test_epilogue_tailcall() is triggered.
37	 * It executes a tail call and control is transferred to
38	 * test_epilogue_subprog(). Only test_epilogue_subprog()
39	 * does args->a += 1, thus final args.a value of 10001
40	 * guarantees that only the epilogue of the
41	 * test_epilogue_subprog is executed.
42	 */
43	memset(&args, 0, sizeof(args));
44	prog_fd = bpf_program__fd(skel->progs.syscall_epilogue_tailcall);
45	err = bpf_prog_test_run_opts(prog_fd, &topts);
46	ASSERT_OK(err, "bpf_prog_test_run_opts");
47	ASSERT_EQ(args.a, 10001, "args.a");
48	ASSERT_EQ(topts.retval, 10001 * 2, "topts.retval");
49
50done:
51	epilogue_tailcall__destroy(skel);
52}
53
54void test_pro_epilogue(void)
55{
56	RUN_TESTS(pro_epilogue);
57	RUN_TESTS(pro_epilogue_goto_start);
58	RUN_TESTS(epilogue_exit);
59	RUN_TESTS(pro_epilogue_with_kfunc);
60	if (test__start_subtest("tailcall"))
61		test_tailcall();
62}